Version 3.63

Chandra Models Version 3.63

This release includes PR #144, which includes a full refit of most ACA parameters, the removal of the two recent step power inputs, and a repurposed heater power input to model the impact of the periscope heater on the ACA CCD temperature. Additionally, the bad time span in the ACA model for the 2022:231 event was increased slightly.

File Changes

Files Modified:

• chandra_models/__init__.py: version increment to 3.63
• chandra_models/xija/aca/aca_spec.json: full general parameter update, step power inputs removed, heater power input repurposed

Files Added:

• None

Files Removed:

• None

Additional Release Information:

• Release Link: https://github.com/sot/chandra_models/releases/tag/3.63
• Diffs: 3.62...3.63
• aca_spec.json MD5: 7619a24b714e3c1e76b76eeb26241135
• __init__.py MD5: 47e49c5e83f4358715d4b8a5e2f97b5e
• Latest Commit: 3446e16 7499ac54ebd8c82ae59eea55012f6f902
• Required xija version: 4.29.1+

Version 3.62

This release includes PR #143, which includes a full refit of most ACA parameters as well as the addition of a new step power input to mitigate a recent increase in model error.

Files Modified:

• chandra_models/__init__.py: version increment to 3.62
• chandra_models/xija/aca/aca_spec.json: full general parameter update, new step power input

Files Added: None

Files Removed: None

Version 3.61

This release includes PR #141 and PR #142. PR #141 copies the contents of the current ACIS FP production model in acisfp_spec_matlab.json into the file under the previous filename, acisfp_spec.json, so both files include the current production model parameters. PR #142 updates the HRC CEA model with a full parameter refit to mitigate the recently observed increase in model error.

Files Modified:

• chandra_models/init.py: version increment to 3.61
• chandra_models/xija/acisfp/acisfp_spec.json: updated to match contents of production model
• chandra_models/xija/hrc/cea_spec.json: full parameter update

Files Added: None

Files Removed: None

Version 3.60

This release includes PR #139 and PR #140; PR #139 updates the ACA model with a new power step parameter to reflect the change in behavior observed near 2024:247. No other parameters were adjusted, and no additional fitting was performed. The ACA planning limit was also increased to -2.7C. PR #140 adds two new limits to the OBA model as placeholders for upper gratings-specific limits that may be used in the future. They are currently set to match the existing general planning limit of 112F. No performance impacting changes were made to the OBA model.

Files Modified:

• chandra_models/__init__.py: version increment to 3.60
• chandra_models/xija/aca/aca_spec.json: Power step added, limit updated
• chandra_models/xija/fwdblkhd/4rt700t_spec.json: placeholder limits added

Files Added: None

Files Removed: None

Version 3.59

This release includes PR #137 and PR #138, which updates the OBA model with a full refit and a limit increment to 112F and increments the tank planning limit to 125F.

Files Modified:

• chandra_models/init.py: version increment to 3.59
• chandra_models/xija/fwdblkhd/4rt700t_spec.json: full model refit, planning limit increment to 112F
• chandra_models/xija/pftank2t/pftank2t_spec.json: planning limit increment to 125F

Files Added: None

Files Removed: None

Version 3.58

This release includes PR #136, which updates the ACIS FP thermal model with a fully refitted version. This update specifically improves accuracy during schedules which alternate between HRC and ACIS observations in the pitch range of ~100-120 degrees. Fits were performed for 365 days of data stopping at until 2024:268 except the dP solarheat parameters, which were fit over 800 days of data.

Changes implemented

• Implemented SIM-Z dependent pitch bins for the 1cbat node
• Implement a new MsidStatePower component for 215pcast for times when the HRC is on and observing
• General re-fit of parameters

Files Modified:

• chandra_models/__init__.py: version increment to 3.58

Files Added:

• chandra_models/xija/acisfp/acisfp_spec_matlab.json: Full model refit, with some structural changes required FOT Matlab Tools changes

Files Removed: None

Version 3.57

This release includes PR #135, which updates the MUPS1B thermal model with a fully refitted version. Fit included data for at least five years, ending on 180:2024.

Files Modified:

• chandra_models/init.py: version increment to 3.57
• chandra_models/xija/mups_valve/pm1thv2t_spec.json: Full model refit

Files Added: None

Files Removed: None

Version 3.56

This release includes PR #134, which adds a new ACA acquisition probability model that will become the new default flight model. This new model is based on flight data plus recent data from the ACA software test set and 2022 data from the ASVT PEA test set.

This model file was created and validated with:

• https://github.com/sot/aca_stats/blob/5ee69ee908cee4f91debad701f2d21b36bcaef2f/fit_acq_model-2024-09-local-quadratic.ipynb
• https://github.com/sot/aca_stats/blob/5ee69ee908cee4f91debad701f2d21b36bcaef2f/compare-acq-model-to-flight-data.ipynb

Files Modified:

• chandra_models/__init__.py: version increment to 3.56

Files Added:

• chandra_models/aca_acq_prob/grid-local-quadratic-2024-09.fits.gz

Files Removed:

• None

Version 3.55

This release includes PR #133, which updates the ACIS FP thermal model in a way that does not require a revision to the MATLAB FOT Tools. This enables better predictions for the ACIS FP temperature in the interim, compared to the version in Chandra Models 3.54, while we wait for another model that requires FOT Tools changes to be included.

Fits were performed for ~300 days of data stopping at until 2024:200, except the dP solarheat parameters which were fit over 900 days of data.

Model Changes implemented

• Update solarheat epoch to a more recent time
• Added new dP parameters near pitches of ~100-110
• General re-fit of parameters
• Add one bad time for recent safing action

Files Modified:

• chandra_models/init.py: version increment to 3.55
• chandra_models/xija/acisfp/acisfp_spec.json: Full model refit

Files Added: None

Files Removed: None

Version 3.54

This release includes chandra_models PRs #130 and #131.

• PR #130 updates the MUPS planning limit to 220F, consistent with the currently approved guideline
• PR #131 updates the ACA model parameters to improve accuracy

Files Modified:

• chandra_models/__init__.py: version increment to 3.54
• chandra_models/xija/mups_valve/pm1thv2t_spec.json: Limit updates only
• chandra_models/xija/mups_valve/pm2thv1t_spec_matlab.json: Limit updates only
• chandra_models/xija/aca/aca_spec.json: Full parameter refit

Files Added: None

Files Removed: None